


This Thing We're Doing

by LadyDrace



Category: Teen Wolf (TV)
Genre: Alternate Universe, Alternate Universe - Fusion, Alternate Universe - Harry Potter Setting, Anal Fingering, Anal Sex, Bottom Derek Hale, Established Relationship, Horny Teenagers, M/M, Teenagers, Top Stiles Stilinski, safe sex
Language: English
Status: Completed
Published: 2014-11-15
Updated: 2014-11-15
Packaged: 2018-02-25 11:30:15
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,865
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2620184
Author URL: https://archiveofourown.org/users/LadyDrace/pseuds/LadyDrace
Summary: <blockquote class="userstuff">
              <p>Stiles has no idea what this is, but it beats the hell out of dealing with Derek's disapproving eyebrows from across the room.</p>
            </blockquote>





	This Thing We're Doing

**Author's Note:**

> This is a commission for the lovely [Kat](http://disturbed-katten.tumblr.com/). Thank you so much, lovely!
> 
> Unbetaed, but thoroughly spell-checked. See end notes for details on underage warning.

“Hale, _please_ show Stilinski how it's done,” Professor Harris drawls, and Stiles sputters with outrage. He didn't fuck up _that_ badly.

 

But Harris hates him. And since the douche-teach is also an observant asshole he has of course also noticed that nothing riles up Stiles more than being paired with Derek, and there's no way to stop the fuming when Derek scoops up his cauldron and beakers and moves to Stiles' desk with a goddamn smirk on his face. Okay, so maybe the fuming isn't just coming from Stiles' anger-hot cheeks, but possibly also slightly from the green-brown sludge in his own cauldron. Shit, he did fuck up.

 

Derek is going to be _such_ a pain in the ass.

 

“Don't say a word, dude. Not. A. Word,” Stiles hisses, and vanishes his ruined potion with a wave of his wand.

 

The problem is, Derek doesn't even have to use words to mock Stiles. It freakin' annoying, that's what. But Harris is glaring at Stiles, so he bites down on his angry muttering, and starts making the potion from scratch again, forcing himself not to jab his wand into Derek's hand every time he reaches over to adjust Stiles' grip on the ladle or to point out a measurement he needs to fix.

 

By the end of class, Stiles' potion is looking promising, but definitely not finished, since he wasted half the class messing it up. He counts himself lucky that Harris doesn't fail him on principle. Harris _does_ dock points from Slytherin, though, and Jackson is going to be be such an enormous douchebag about it. Stiles curses whatever evil magic put him in the same house as Jackson _asshole_ Whittemore.

 

Derek catches up with him after lunch, just managing to catch him as he's about to speak the password to the dorm.

 

“Come to gloat a little more?” Stiles spits, and pointedly does not _say_ the password in earshot of a Ravenclaw.

 

“No,” Derek says softly. “I came to...”

 

“To what.”

 

The lack of question mark at the end of his sentence clues Derek in that he's stepped in it.

 

“To make it up to you. I can't help that I'm better than you in potions, but I know I wasn't making it easier for you either.”

 

“You _think_?”

 

A warm hand lands on Stiles' shoulder, and he relaxes slightly despite himself. He hates that Derek can do this to him, no matter how angry they are at each other.

 

“Stiles,” he says softly. “Please don't be angry with me.”

 

“Well, I am. Sucks to be you, _Hale_ ,” he snarls, and shakes off Derek's hand.

 

There's silence behind him for a long moment, and the quiet scuff of boots on the floor makes it clear that Derek is shifting with unease. Suits him right.

 

“Lemme make it up to you, then,” Derek says finally. This makes Stiles turn around and face him, one eyebrow raised.

 

“Oh, really. What could you possibly offer me that would make up for having Jackson on my ass the second he realizes who got those points docked from our house?”

 

Derek does a quick check that they're alone, and moves in until they're nose to nose. “What we did... last Tuesday. We could... go somewhere and... do it again?”

 

Stiles has to swallow really hard, because he's sixteen and brimming with hormones, and thanks to Derek he now has actual experience. Not much, but still! Not a virgin anymore! And knowing now what he's been missing makes it so much harder for Stiles to set his jaw and shake his head.

 

“No thanks,” he grits out, and Derek's face falls for a second. But he recovers and leans in just a little more, nuzzling his nose against Stiles' cheek.

 

“We could... do it... the other way around.”

 

This gets Stiles' attention so fast he almost breaks his nose against Derek's from snapping his head around so fast.

 

“You mean... me... doing the... thing. To you?”

 

Derek glances at a nearby painting which is not being remotely subtle about eavesdropping. “Yeah. Yeah. I want you to,” he whispers.

 

And okay, Stiles might be a man of principles, but he's also a man who has needs, okay? Like needs to get somewhere private and do many amazing things to Derek's naked body.

 

“Gimme a minute,” he croaks, and sputters the password so fast Derek probably doesn't hear it anyway, and darts inside to dump his things and get... supplies. Magic or not, some things you just do not want to cut corners on.

 

Seeing as Derek is a prefect, there's not even an issue of where to go. Prefects have their own bathrooms, locker rooms and a couple of smaller rooms for studying or napping between classes. And best of all... there are zero nosy paintings on the walls. So they rush to the nearest one, and while Stiles locks the door behind them, Derek waves his wand to change the room's setting from studying setup to one with a fairly nice bed. It's only a single, because despite the fact that everyone knows what a lot of prefects get up to in these rooms, it wouldn't do to encourage them. Stiles has his eye on an expanding charm, though, but for now they're eager and horny enough not to care. Especially if Derek was serious about his offer.

 

Stiles almost topples them both over when he rushes at Derek, attacking him with hungry kisses. He yanks at the robe covering up those gorgeous abs he only got the barest glimpse of last time, and _that_ is just a crime.

 

“Off, off, _off_ ,” he huffs, and feels a little better for his impatience when Derek gets his head stuck in his eagerness to get his clothes off.

 

They somehow manage to fumble their clothes off, and there's a tiny thunk from Stiles' robes when the supplies in his pocket hits the floor and reminds him of them. He digs out the small pouch from his pocket, fishes a small jar out of it, and Derek raises an eyebrow at him.

 

“What?” Stiles asks. “You brought it last time, I thought it was my turn.”

 

Derek squints at the jar. “Did you make it yourself?”

 

Stiles snorts. “Well, yeah, would _you_ feel good about asking your friend or – _holy fuck_ , Madam Pomfrey! To whip up a batch of anal friendly lube? I don't think so!”

 

The jar disappears from Stiles' hand, and he glares at Derek who doesn't even have the grace to look ashamed, wand out and everything. “Okay, what the hell?!”

 

“Stiles, I am going to say this as bluntly as I can. You suck at potions. I mean, yeah, you pass, but to trust your mediocre grades enough to let you put any of this on my body? No thanks. I brought my own.”

 

“Look, asshole, you might be insanely hot, but you're not exactly getting me in the mood by insulting me, you know!” Stiles snaps, but Derek just summons a jar of his own from the pocket of his robe, which ended up flung into a corner, and presses it into Stiles' hand.

 

“We can debate your skills at potions later. Right now, all you need to know is that I really like you, and I want you to fuck me.”

 

And yeah, that's more than enough for Stiles to push his affront aside and get down to the business of sex. Derek is naked on the bed. Like... really amazingly _naked,_ and damn, how did Stiles even manage to get distracted from that?

 

But, of course, Derek, being the fastidious bastard that he is, stops Stiles before he even gets to touch. “Okay, what now?!”

 

“Safety,” Derek insists, and yes, okay, now Stiles feels bad, because he should know this shit.

 

“Right, yes.”

 

It's commonly known that the basket just inside the door in Madam Pomfrey's office is always full of small bottles that students can take as needed. Most choose to do it when she's not in, or summon them from around the corner, but even if they show up in person, there are no questions asked and not a hint of judgement. It's an unwritten, but universally known, truth that Madam Pomfrey will much rather spend her time brewing up safety potions than having to deal with teen pregnancies or genital guffles.

 

So Stiles has had two of the small bottles tucked away under his bed since his first week here, stupidly hopeful of actually getting to use them at some point, and naturally Derek made that disapproving face when he saw the date on the label, and vanished those too. Not doing great things for Stiles' self confidence here.

 

But this time he has brand new ones, and Derek accepts one from him with a small smile that does disastrous things to Stiles' insides, and they clink the tiny bottles in a toast before draining them and letting them drop to the floor.

 

Derek Hale is gorgeous, no one with eyes would dispute that, and it's still mind-boggling to Stiles that he somehow won the lottery with this. Especially considering that they're not even friends. Fuck-buddies at best, if a single frenzied hook-up counts. But whatever, Stiles will take what he can get.

 

And right now, it seems, he can get all his hottest dreams served up on a silver platter. Derek lets himself flop back onto the bed, arms behind his head, well aware of his allure. _Fucker_. But he grins when Stiles clambers gracelessly up his body and kisses him wetly, just because he can.

 

“How do you... how do you wanna...” Stiles tries to ask. It feels polite, because Derek had asked him the same thing last time.

 

“Like this,” Derek says softly. “So I can see you.” He looks almost bashful, and Stiles feels a ridiculous amount of fondness for him, as well as a healthy dollop of joyous disbelief that Derek freakin' Hale thinks that he's anything worth looking at.

 

Derek's legs fall open invitingly, his... well, _everything_ on display. He's hard, so at least he seems just as enthusiastic as Stiles. And seeing as Stiles isn't exactly a wealth of experience here, he just does what Derek did to him the last time. From the half-lidded, slack-jawed face Derek makes, Stiles figures he isn't doing too bad when he settles down between the open knees, and licks his lips. Hell yeah. This is gonna be amazing.

 

He licks a wet stripe up Derek's cock, and it jumps under his tongue. The taste is new and exciting to Stiles, since last time he was too busy coming his brains out to get his own turn. He spends a few minutes just licking and nipping at it, sucking briefly at the head, earning him a startled gasp of pleasure from Derek, before fumbling for Derek's jar of slick and getting some on his fingers.

 

Stiles glances up at Derek's face to make sure everything is still fine, and carefully circles the rim with one finger, while still tonguing at the nice, blushing dick right in front of his face. He presses in carefully with only a single fingertip, and Derek clenches his stomach muscles briefly before relaxing, and Stiles' own cock twitches from the sheer hotness of it all when his finger just slides right into the scorching heat.

 

“Oh my god,” he breathes, cautiously sliding his finger out and then back in before remembering how Derek had distracted him last time, and goes back to licking around the head of his cock, which makes him groan in a way that makes Stiles' pulse race.

 

Two fingers go in almost as easy, Derek clearly concentrating hard on accepting the intrusion, and Stiles does his very best to distract him with his amateur blow job skills. He worries that he's not doing very well, since Derek's cock is losing a little bit of its hardness when Stiles tries for a third finger. But Derek is panting and clawing at the sheets, and only lets Stiles work him open for another minute or so before pushing him away.

 

“I'm good. Want _you_ now.”

 

Stiles is not gonna argue. _Hell no_.

 

His hand shakes on his cock as he gets in position and starts pressing inside. Derek's eyes are clenched shut, and he's stroking his own cock slowly, like he's not even aware of it. Stiles watches his face, and after the third wince he stops, lead sinking in his gut.

 

“Dude, if it hurts you, I'm not gonna-”

 

“It'll pass,” Derek grunts. “Just... slowly. I want it. I want _you_. Just gimme a minute, okay?”

 

If Stiles had been older and more experienced, he might have argued. But as it is, his dick is half way to heaven, and giving it up now is just too much when Derek is literally asking for it. He does try and change position slightly, bending Derek's knees up a little further, hooking his elbows under them to keep them there. His arms are straining, seeing as he's not exactly the strongest kid in school, but Derek's brows uncrease slightly, and Stiles slides the last of the way inside slowly but smoothly.

 

Once he's bottomed out he waits, gnawing the skin off his lip as Derek strokes his own cock back to life after its loss of interest. But Derek hadn't been lying, and only a minute or so later he breathes out a sigh, and loses the pinched look on his face.

 

“Go on,” he rasps. “Slowly.”

 

Stiles does his best. It's probably too fast, but Derek only winces once or twice more before his cock is back to full hardness, and he starts panting in a very encouraging way. And then he opens his eyes, watching Stiles thrust into him unevenly, sweating and wheezing, because holy crap, this shit takes more effort than he'd thought.

 

But Derek's eyes feel like flames on his skin, and he thrusts harder, the sound of their skin slapping together loud and filthy, sweat dripping from his brow into his eyes. Derek reaches up with one hand to thumb a droplet out of Stiles' eyebrow, and then brings it to his lips, because he's a weirdo like that. But obviously weird turns Stiles the fuck on, and he lets out a shocked moan as Derek flashes his adorable bunny teeth at him in a smug grin, and starts jerking himself faster.

 

“Jesus Christ,” Stiles wheezes, and Derek nods, eyes looking kinda glazed now.

 

“Yeah. Yeah. _Fuck_ ,” Derek agrees, eyes locked on Stiles' face. “Yes, more. Faster.”

 

 _Faster._ Stiles can do faster. Most definitely.

 

He's pretty sure he looks ridiculous as he slams into Derek, off-rhythm and too desperate to be all that good, but Derek looks like he's really into it, his cock leaking in his hand, and his mouth hanging open with every gasping breath.

 

“Yes... yes... _yes_...” he whispers, and just like that he scrunches his eyes shut, and comes all over his own stomach, jerking himself so fast that it looks like a blur. Stiles feels it like a punch in the gut, and drops Derek's legs so he can brace himself on the mattress. He's breathing right into Derek's face as he ruts into him, and Stiles worries for a brief, distracted moment if his breath is okay. Derek seems to think so, because he reaches up and drags Stiles close by the back of his neck, and licks into his mouth as if Stiles is the best thing he's ever tasted.

 

Derek parts their lips again, only to look Stiles right in the eye and say: “Fuck, you're amazing. I like you so much.”

 

And apparently Stiles has a major feelings-fetish, because he makes an embarrassingly loud grunting noise, and comes so hard he almost blacks out. Derek sighs under him and kisses him through it, and when it finally winds down, Stiles breathes a deep, satisfied sigh, and collapses on Derek's chest.

 

“Dude,” Stiles wheezes. “Don't say shit like that. I might end up thinking you mean it.”

 

“I do,” Derek says quietly.

 

Stiles raises his head slowly to squint at him. “You do not. All you ever do is nag or glare at me!”

 

“All I ever do is follow you around, because I wanna be near you all the time,” Derek counters, and that shuts Stiles up for a full minute. He stares at Derek's face, but all he sees is a slight blush, as if Derek is the one having his life turned upside down right now.

 

“Well... maybe you should try being nicer to me, then. Seriously, just try. I'd put out for you all the time if you just cut down on the judgemental eyebrows, man.”

 

“I am trying.”

 

Stiles glares.

 

“But... I'll try harder.”

 

“You're gonna have to,” Stiles huffs. “Because I am _not_ dating an asshole.”

 

Derek is quiet for a long tense moment. “Dating?”

 

“Unless you don't want to,” Stiles says, hoping his voice is steady.

 

“I want to.” Derek's voice is not steady. There's no way Stiles can stop the gigantic smile growing on his face.

 

“Awesome. Yeah. It's gonna be awesome.”

 

End.

 

**Author's Note:**

> About the underage warning: Stiles is 16 and Derek is older, but unspecified.
> 
> EDIT: also, I realized literally years after the fact that I goofed up about where the Slytherin dorms are. I've fixed it now, but oh god, the shame.


End file.
